Tappets/lifters - Ticking?

[spetz]

My friends 6A12 MIVEC does quite a bit of ticking on idle but you can still hear it at revs over idle.

A mechanic said that lifters need changing? But I was always aware that the FTO tappets are adjustable and it can be made silent by bringing the clearances to correct specifications?

If this is the case what are the specifications???

[mrx]

Firstly - search....

Secondly: GR's are hydraulic and can be replaced or even cleaned. GPX lifters are adjustable, but a b!tch of a job without the right equipment.

With a GPX, the top screw part may need replacing if the little platic "hat" has broken off.